the last word

Photography meets digital computer technology. Photography wins -- most of the time.

  • site home
  • blog home
  • galleries
  • contact
  • underwater
  • the bleeding edge
You are here: Home / Color Science / Why no love for Luv?

Why no love for Luv?

May 13, 2022 JimK 2 Comments

I’ve always liked looking at colors  and color relationship in both CIEL*a*b* and CIEL*u*v*. Neither is perfectly perceptually uniform, and on average, they’re both about the same distance away from that. A couple to times I’ve looked at averaging the two, but nobody else does that, so I haven’t published any of those graphs.

But nobody here talks about Luv. Why is that?

Lab and Luv come from different industries. The ancestors of Lab were used in the printing industry and in assessing hard copies. The forbearers of Luv were in industries that used self-luminous displays. They were both codified at the same time, about 13 years before I got involved in color science professionally. I’ve been out of the biz for going on 30 years now, so I’m unaware of how the color space politics has progressed.

Was Photoshop’s late-80s decision to support Lab but not Luv important? Maybe so. I’ll be many photographers got their introduction to Lab through Ps.

The ICC’s blessing of Lab as the reference space may have also played a role.

And then there’s the fact that Lab has been enhanced over the years since 1976, while I don’t think that Luv has received any improvements.

Is this a QWERTY thing? At the beginning of Ps, the program was mostly aimed at post production for printing. Now, it seems like most people are thinking more about self-luminous media. But maybe the die was cast?

Luv has some nice features. It has a saturation metric that makes a lot of sense. The derivation from XYZ, while having its share of heuristic decisions, seems less so that Lab. The ability to include the spectral horseshoe on chromaticity plots is a plus.

But I don’t see people using it. The reason that working photographers don’t use it has to hinge on the fact that it’s not supported in the reference tool. But why isn’t it?

Color Science

← Gamut of a basis-function derived metamer set Subscribe to comments — going once… →

Comments

  1. JaapD says

    January 12, 2023 at 11:00 am

    Hi Jim,
    Thanks for this post. I really like Lab. I use(d) it for my sharpening action where I only apply sharpening in the luminance channel, leaving the color channels unaffected. From experience I can say that with this I’m able to apply a more natural sharpening before the end result gets over the top.

    (background info: I copied this ‘trick’ from the old 3 CCD / 3 Plumbicon analog image processing pipeline with the broadcast cameras where sharpening was also applied only in the luminance channel, leaving the color difference channels unaffected)

    Cheers,
    Jaap.

    Reply
    • JimK says

      January 12, 2023 at 12:00 pm

      Yes. I used to do that in the early 90s. I think that would work equally well in Luv.

      Reply

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

February 2023
S M T W T F S
 1234
567891011
12131415161718
19202122232425
262728  
« Jan    

Articles

  • About
    • Patents and papers about color
    • Who am I?
  • Good 35-70 MF lens
  • How to…
    • Backing up photographic images
    • How to change email providers
  • Lens screening testing
    • Equipment and Software
    • Examples
      • Bad and OK 200-600 at 600
      • Excellent 180-400 zoom
      • Fair 14-30mm zoom
      • Good 100-200 mm MF zoom
      • Good 100-400 zoom
      • Good 100mm lens on P1 P45+
      • Good 120mm MF lens
      • Good 18mm FF lens
      • Good 24-105 mm FF lens
      • Good 24-70 FF zoom
      • Good 35 mm FF lens
      • Good 60 mm lens on IQ3-100
      • Good 63 mm MF lens
      • Good 65 mm FF lens
      • Good 85 mm FF lens
      • Good and bad 25mm FF lenses
      • Good zoom at 24 mm
      • Marginal 18mm lens
      • Marginal 35mm FF lens
      • Mildly problematic 55 mm FF lens
      • OK 16-35mm zoom
      • OK 60mm lens on P1 P45+
      • OK Sony 600mm f/4
      • Pretty good 16-35 FF zoom
      • Pretty good 90mm FF lens
      • Problematic 400 mm FF lens
      • Tilted 20 mm f/1.8 FF lens
      • Tilted 30 mm MF lens
      • Tilted 50 mm FF lens
      • Two 15mm FF lenses
    • Found a problem – now what?
    • Goals for this test
    • Minimum target distances
      • MFT
      • APS-C
      • Full frame
      • Small medium format
    • Printable Siemens Star targets
    • Target size on sensor
      • MFT
      • APS-C
      • Full frame
      • Small medium format
    • Test instructions — postproduction
    • Test instructions — reading the images
    • Test instructions – capture
    • Theory of the test
    • What’s wrong with conventional lens screening?
  • Previsualization heresy
  • Privacy Policy
  • Recommended photographic web sites
  • Using in-camera histograms for ETTR
    • Acknowledgments
    • Why ETTR?
    • Normal in-camera histograms
    • Image processing for in-camera histograms
    • Making the in-camera histogram closely represent the raw histogram
    • Shortcuts to UniWB
    • Preparing for monitor-based UniWB
    • A one-step UniWB procedure
    • The math behind the one-step method
    • Iteration using Newton’s Method

Category List

Recent Comments

  • Brian Olson on Fuji GFX 100S exposure strategy, M and A modes
  • JimK on Picking a macro lens
  • JimK on Picking a macro lens
  • Glenn Whorrall on Picking a macro lens
  • JimK on What pitch do you need to scan 6×6 TMax 100?
  • Hatzipavlis Peter on What pitch do you need to scan 6×6 TMax 100?
  • JeyB on Internal focusing 100ish macro lenses
  • JimK on How focus-bracketing systems work
  • Garry George on How focus-bracketing systems work
  • Rhonald on Format size and image quality

Archives

Copyright © 2023 · Daily Dish Pro On Genesis Framework · WordPress · Log in

Unless otherwise noted, all images copyright Jim Kasson.